Whenever Sunset Shimmer was out at work, and Flash Sentry was trying to slowly regain his normal size after his "belittling" from a prior flub-up with his girlfriend, he and his fellow school-mate, Vanilla Beam, would sit at home and play some of Sunset's video game catalog, with her permission, of course.
She would have only one rule: do NOT overwrite any of her save files. She spent hours, DAYS even, on her games to get the best scores, and it would be a shame if her data got deleted.... welp, now the boys have some explaining and confessing to do.
One of them HAD to do it, and Sunset will DEFINITELY get the truth out, one giant way or another.
All that growing progress for Flash, gone in a single sentence.